Fall protection safety devices are well known in the art of fall protection safety equipment for use by workers performing tasks during which there is a risk a fall may occur.
One type of safety device commonly used is a rail along the length of which a shuttle moves. The rail is typically connected to a support structure within the vicinity the worker is performing the task, and the shuttle is typically connected to a safety harness worn by the worker. An energy absorber may also be used with this type of safety device to reduce the amount of force transferred to the worker. Should a fall occur, the shuttle locks onto the rail thereby preventing the worker from falling any further. If the shuttle becomes contaminated with dirt, oil, grease, water, ice, or other types of debris or contaminants, the shuttle may not operate properly. One type of commonly used shuttle utilizes a wheel that rides on a rail or track to sense speed, and the wheel could be affected by contaminants. If the wheel has a rubber grip, the rubber grip could be degraded by ultraviolet light or ozone exposure.
Another type of safety device commonly used is a self-retracting lifeline. A self-retracting lifeline generally includes a housing containing a drum around which a cable, rope, webbing, or other suitable lifeline is wound. The drum is spring biased to pay out cable as tension pulling the cable is applied and to retract any of the cable that has been unwound from the drum as the tension on the cable is reduced or released. The housing also includes a brake assembly for stopping rotation of the drum when the cable suddenly unwinds from the drum at a rate greater than a predetermined maximum angular velocity. A self-retracting lifeline is typically connected to a support structure within the vicinity the worker is performing the task, and the end of the cable is typically connected to a safety harness worn by the worker. The support structure may include one or more structures. The cable is easily drawn out of the self-retracting lifeline housing as the worker moves away from the device, and the cable is automatically drawn back into the housing as the worker moves toward the device. Should a fall occur, the brake assembly within the device is automatically engaged by a centrifugal clutch assembly, which gradually and quickly stops the worker's fall by gradually and quickly stopping the rotation of the drum. As the rotation of the drum is stopped, additional cable is prevented from being paid out of the housing to stop the fall of the worker. Some self-retracting lifelines are sealed to prevent contaminants from interfering with the braking or locking mechanism.
Another type of safety device commonly used is a descender or a controlled descent device, which generally include a braking mechanism to allow the worker to slowly descend to a safe location.
For the reasons stated above and for other reasons stated below, which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for a shuttle for use with a fall protection assembly that is less prone to contaminants interfering with its operation.